Web registry for flexographic presses



Dec. 17, 1968 L. .1. CAHN WEB REGISTRY FOR FLEXOGRAPHIC PRESSES OriginalFiled Oct. 16, 1962 e She ts-Sheet 1 INVENTOR.

QNN EzE 5725mm Q9 NM E255 6528 wsw LEON .J. CAI-IN v ATTORNEY Dec. 17,19 8 L. J. CAHN WEB REGISTRY FOR FLEXOGRAPHIC PRESSES Original Filedoat. 16, 1962 1/20 I24 I22 195-1 60 {5 2a 2/4 I 6) M204 211g z0a\ /54 54M 192 4 M 14 INVENTOR.

e Sheets-She et z LEON u. CAH N ATTO R N EYS Dec. 17, 1968 L. J. CAHN 3,,4

WEB REGISTRY FOR FLEXOGRAPHIC PRESSBS Original Filed Oct. 16, 1962 6Sheets-Sheet 5 W .144 F I G- 6 f 24/ I:

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L EON J. CAHN ATTO RN EYS.

Dec. 17, 1968 J. CAHN, 3,416,444

' WEB REGISTRY FOR'FLEXOGRAPHIC PRESSES' 6 Sheets- Sheet 4 OriginalFiled Oct. 16, 1962 INVENTOR. LEON .1. CAHN ATTORN EYS L. J. CAHN WEBREGISTRY FOR FLEXOGRAPHIC PRESSES Original Filed Oct. 16, 1962 Dec. 17,1968 6 Sheets-Sheet 5 N H @A mc V J N o E ATTORNEYS Dec. 17, 1968 J.cAHN I WEB REGISTRY FOR FLEXOGRAPHIC PRESSES Original Filed Oct. 16,1962 6 Sheets-Sheet 6 FIC5.II

Faaus INVENTOR. LEON J. CAH N ATTORN EYS United States Patent 3,416,444WEB REGISTRY FOR FLEXOGRAPHIC PRESSES Leon J. Cahn, Long Islands City,N.Y., assignor to Lee .Machinery Corporation, New York, NY. Originalapplication Oct. 16, 1962, Ser. No. 230,953, now Patent No. 3,233,539,dated Feb. 8, 1966. Divided and this application Sept. 16, 1965, Ser.No. 487,823

4 Claims. (Cl. 101181) ABSTRACT OF THE DISCLOSURE A web registry meansfor a flexographic press having multiple printing stations wherebyrollers are employed intermediate a. pair of printing stations and arecaused to enter into greater or lesser contact with the non-indiciabearing surface of the web passing through said printing stations toobtain the proper registry of the printed indicia on the web.

This is a divison of application Ser. No. 230,953, filed Oct. 16, 1962,now US. Patent 3,233,539.

The present invention relates to printing presses and, moreparticularly, to presses generally known as flexographic presses.

Flexography or aniline printing is a specialized form of relief printingfor printing on materials; such as, cellophane, polyethylene, which havesurfaces not capable of being handled by ordinary letter press methodsof printing. In flexographic presses the printing is accomplishedgenerally by flexible rubber plates carried by the printing cylinders ofweb-fed rotary presses. The rubber plates are generally inked by asingle inking roller and the material to be printed is fed between thepress plate cylinder and its associated impression cylinder.

Generally, these flexographic presses print multiple colors with a platecylinder and coacting impression cylinder, each associated with aparticular color to be printed. It will be understood that in multipleink work, proper registration of the web between successive printingstations in the press is critical. Heretofore, however, the pressgenerally had to be stopped to reregister the web, which istime-consuming and costly.

The present invention is characterized by the provision of means forensuring proper registration between successive printing stations whilethe press is running. Between successive printing stations there isprovided a compensator roller mounted for movement toward and away fromthe web and against the surface thereof not being printed. Thecompensator roller momentarily increases or decerases the tension in theweb between printing stations, thereby effecting a retarding or speedingup of the web between successive printing stations. Thus, the operatorcan control the running web to maintain proper registry an essentialfeature for multiple color printing and not heretofore available inflexographic printing.

Likewise, in flexographic presses for multiple color (generally, fourcolors), it may be desirable to print only two colors or it may bedesirable to deactivate all printing stations during web replacement.Accordingly, means are provided in the present invention for deactuatingby means of a single lever the four printing stations. A linkagearrangement is provided whereby a single lever movement effects lateralmovement of the four printing cylinders away from their relatedimpression cylinders. Means is also provided for moving the printingcylinders on each side of the press away from their associated inkingrollers. An actuator handle and link arrangement effects intermovementof these printing cylinders toward and away from their associated inkingrollers when only two color printing is desired. Thus, the arrangementspermit the "ice ink fountain rollers :and/or plate cylinders to continueto rotate, agitating the ink, while the printing is temporarilyinterrupted, thus preventing ink from accumulating on the platecylinders and/or ink fountain rollers.

To provide for ready access to the ink fountains for maintenance andother reasons, each ink fountain is removably supported on spaced cams.In their upward position the cams locate the ink fountains adjacent tothe ink fountain roller. In their downward position, the ink fountainsare spaced from their fountain rollers. This simple arrangement providesfor ready access to the press ink fountains Without the unboltingrequired heretofore.

Generally, fiexographic presses are run roll-to-roll with the printingweb being rewound. To insure proper tension and web rewind, there isprovided automatic control means responsive to web slack for increasingor decreasing the speed of the rewind motor. This control means includesa counter-weighted dancer roller, electrically associated with avariable speed motor in turn driving the web rewind shaft. As the dancerroller position changes in accordance with the web tension, the rewindmotor is driven faster or slower in response thereto to maintain theproper tension in the web and proper web rewind feed.

Likewise, to facilitate tearing of the imprinted web when such tearingis desired, the press of the present invention includes a scoringmechanism operative, after the web has been completely imprinted, toprovide longitudinal score lines in the printed web as it travels towardthe press rewind section.

Objects It is therefore the object of the present invention to provide anovel flexographic printing press.

It is also an object of the invention to provide in a fiexographicprinting press, novel means for maintaining registry of the running webbetween successive printing stations.

A further object of this invention is to provide in a flexographicprinting press, novel means for maintaining registry of the running webbetween successive printing stations, including web tension controlmeans for effecting the web travel rate between successive printingstations.

Another object of the invention is to provide in a flex-ographicprinting press novel means for supporting and simultaneously moving thepress printing cylinders laterally toward and away from their associatedimpression cylinders, including a single lever actuator and relatedlinkages.

It is an added object of the present invention to provide in aflexographic printing press having a plurality of printing stations withat least one on each side of said press, novel linkage means mountingand supporting the ink fountain rollers on each side of said press forsimultaneous movement toward and away from their associated inkingrollers by the single movement of a linkage actuator.

Another object of the present invention is to provide a novel web rewindmechanism response to web tension for increasing or decreasing the rateof web rewind whereby proper web tension is maintained during rewind.

A further object of the invention is to provide in a flexographicprinting press, means for selectively controlling the rate of web rewindin accordance with web tension, including a counter-weighted dancerroller electrically associated with the web rewind means.

An additional object of the invention is to provide rotatable camsupports for the ink fountains of a fiexographic printing press wherebysaid fountains are readily movable from their operative inking positionfor desired access thereto.

It is likewise an object of the present invention to provide in aflexographic press novel score means for cutting longitudinal scorelines in the web running through said press.

Other objects and advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be leaned bypractice with the invention, the same being realized and attained bymeans of the instrumentalities and combinations pointed out in theappended claims.

The invention consists in the novel parts, constructions, arrangements,combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment of the invention, and together withthe description, serve to explain the principles of the invention.

FIG. 1 is a schematic view of the web path through the press.

FIGS. 2, .3 and 4 are schematic views illustrating the several positionsof the printing cylinders, ink fountain rollers, ink fountains and webregistration tension control rollers.

FIG. 5 is a schematic view of the rewind section of the press.

FIG. 5A is a sectional view taken along line 5A--5A, FIG. 5.

FIG. 6 is a side elevation of the press embodying the present inventionand illustrating one ink fountain in nonoperative position.

FIG. 7 is a detailed side elevation of the ink fountain and printingcylinder control mechanisms.

FIG. 8 is a perspective view partly broken away of the printing cylindercontrol mechanism.

FIG. 9 is a front view of the printing cylinder control actuating rods.

FIG. 10 is a perspective view partly broken away of the printingcylinder and ink fountain supports.

FIG. 11 is a side elevation partly in section of the ink fountain andassociated elements in operative position.

FIG. 12 is a view taken along line 1212, FIG. 11.

FIG. 13 is a side elevation partly in section of the ink fountain andassociated elements in nonoperative position.

FIG. 14 is a front view of the web registration control roller actuatingmechanism.

General description Referring specifically to FIGS. 1 and 6, thematerial to be printed, preferably cellophane or polyethylene, is fedfrom a supply roll R rotatably carried on shaft 11 by the main frame Fof the four-color flexographic press 10. In normal operation, thematerial web W is fed under inside idler roller 12 and thence arounddraw roller 14, preferably of rubber or similar material. From drawroller 14, web W passes under the lower impression cylinder 16 andbetween impression cylinder 16 and the first printing plate cylinder 18at printing station 1. Web W is then fed successively (a) between upperimpression cylinder 20 and the second printing plate cylinder 22 atprinting station II, (b) over top compensator roller 24, (c) betweenupper impression cylinder 20 and the third plate printing cylinder 26 atprinting station III, ((1) between lower impression cylinder 16 and thefourth printing plate cylinder 28 at printing station IV.

From station IV, printed web W is trained around idler rollers 30, 32,34, 36 and 38, as it travels from press 10 through heated drying tunnelT. It will be understood that in drying tunnel T the ink on web W isdried and set. From tunnel T web W enters the press rewind section,designated generally S.

In section S, web W is first fed around spaced idler rollers 40 and 42.Web W is then brought over the dancer roller 44 and thence aroundanother idler roller 46 and onto reel 49 on rewind shaft 48.

In normal operation, web W is traveled successively through printingstations I, II, III and IV, and at each printing station a separatecolor is imprinted on web W by printing plate cylinders 18, 22, 26 and28. Usually, heat means (not shown) are disposed between successiveprinting stations and in drying tunnel T for hastening the final dryingand setting of the ink deposited on web W. Web W is drawn from roll R bythe coaction of impression cylinder 16 and draw roller 14 which aredriven by a suitable conventional power source (not shown) which mayinclude a variable speed motor and a belt and pulley system. The web Wis also urged through press 10 by the rotation of rewind shaft 48 asdescribed more fully hereinafter.

Printing cylinders and associated mechanisms Printing plate cylinder 18is mounted on a shaft 50 supported at each end transversely in press 10by upright extension 52 of printing plate cylinder frame 54. (See FIGS.7, 8 andlO). Frame 54, in turn, is slidably mounted on a support plate55 seated in a suitable keyway 56 formed in cross-arm 58 of the pressframe F. The ink fountain roller 60 associated with plate cylinder 18 ismounted on a shaft 62 and disposed parallel to cylinder 18. Shaft 62 iscarried at each end in a link arm 64 pivotally connected to an extension66 of the ink fountain carriage 68. Carriage 68 in turn is slidablysupported on a plate 69 mounted in a suitable keyway 70 formed inprinting cylinder frame 54 (see FIG. 10).

Plate cylinder frame 54 is adapted for travel along its associatedsupport plate 55 by means of threaded shaft 57 carried by bracket 59fixed to the end of plate 55 remote from cylinder 18. The turning ofhandle 59 located on shaft 57 is operative to move frame 54 back andforth along plate 55. This arrangement enables printing cylinder 18 tobe moved into contact with its associated printing cylinder 16 at thestart of printing operations and gives press 10 great flexibility in thelength printed therewith.

Likewise carriage 68 is adapted to travel along its associated supportplate 69 by means of threaded shaft 71 carried by bracket 73 fixed tothe end of plate 69 remote from roller 60. The turning of handle 75 onshaft 71 is operative to move carriage 68 back and forth along plate 69as desired.

It is understood that plate cylinder 18 is provided with the samesupport elements at each side of the press 10. However, for brevityssake, only the elements on the side of the press shown have beendescribed in detail. It will likewise be understood that each printingplate cylinder 18, 22, 26 and 28 has the same support elements associtedtherewith and in the interests of brevity a detailed description of theelements of cylinder 18 and station I only is given.

Printing cylinder actuating mechanism Means is provided forsimultaneously moving printing cylinders 18, 22, 26 and 28 into and outof operative position. FIG. 6 shows printing cylinders 18, 22, 26 and 28in operative printing position adjacent their associated impressioncylinders 16 and 20, while FIG. 7 shows the printing cylinders innon-operative position and spaced from the impression cylinders.

To accomplish this, each printing cylinder frame support plate 55 ispivotally attached to one end of a crank arm 72, as best shown in FIG.8. The other end of crank arm 72 is fixed to and rotatable with aneccentric 74. In turn, eccentrics 74 are secured to central shaft 76 forprinting stations I and IV, and to shaft 78 for printing stations II andIII. Shafts 76 and 78 are supported at each end of the press frame F.

Shafts 76 and 78 are also furnished at one side of the press withactuating bars 80 and 82, respectively, Actu ating bars 80 and 82 areinterconnected by a generally vertical link member 84. Bars 80 and 82are rotatable with their associated shafts 76 and 78 and upper shaft 78includes an actuating handle 86 for effecting rotation of its associatedshafts 78.

In operation, to move printing cylinders 18, 22, 26 and 28 from theoperative printing position shown in FIG. 6 to the non-operativeposition shown in FIG. 7, handle 86 is rotated in the direction of arrowA, FIG. 6, to its position shown in FIG. 7. This, in turn, rotatesshafts 76 and 78 through the action of bars 80 and 82, and link member84. Rotation of shafts 76 and 78 moves the high point 75 of eccentrics74 toward their associated printing cylinder frames 54, effectingsliding travel of printing cylinder frames support plates 55 in theirassociated keyways 56, moving the printing cylinder frames 54 locked toplates 55 by shaft 57 away from the associated impression cylinders. Tomove the printing cylinders 18, 22, 26 and 28 into operative positionadjacent their associated impres sion cylinders, the position of handle86 is reversed, in turn reversing the direction of travel of theassociated linkage arrangement to move the printing cylinder framestoward their associated impression cylinders.

Ink fountain roll actuating mechanism Means is provided forsimultaneously moving the ink fountain rollers at stations I and II andat stations III and IV simultaneously away from their associatedprinting cylinders. To accomplish this, the ink fountain carriagessupport plates 69 at stations I and II are each pivotally connected toone end of an associated crank arm 88. The other end of arm 88 ismounted on an eccentric 90 secured to a stud shaft 92, carried byprinting cylinder frame 54. Stud shafts 92 at station I are fixed to oneend of an actuating bar 94. The other end of bar 94 is pivotallyconnected to one end of a generally vertically disposed link member 96.The other end of link member 96 is pivotally attached to one end of anactuating lever 98. Lever 98 adjacent its midpoint, is fixed to androtatable with stud shaft 92 while its free end includes an actuatingknob 100.

To move ink fountains at stations I and II from the nonoperativeposition shown in FIG. 7 to their operative positions shown in FIG. 6,handle 98 is rotated in the direction of arrow B, FIG. 7. This, in turn,will effect a rotation of both stud shafts 92 by the above describedlinkage system. Rotation of shafts 92 by this movement of actuatinglever 98 urges the high point 89 of eccentrics 90 toward impressioncylinders 16 and 20 travelling the ink fountain carriage support plate69 and the carriage 68 thereon toward their associated printingcylinders,

It will be understood that the mechanism for moving the ink fountains atstations III and IV are identical to the described elements for rriovingthe ink fountains at stations I and II, and the detailed descriptionthereof is omitted is the interest of brevity.

Web registry control mechanism As web W travels between printingstations I, II, HI and IV, the speed thereof may vary slightly due topress web or variation in web rewind speed. Such variation betweenprinting stations, however, throws the web 01f registry resulting insuccessive printed images on the web that do not register.

To correct this situation, means is provided for correcting registrationof the web between successive printing stations by increasing ordecreasing the web speed between stations by means of a decrease orincrease of the web tension. To accomplish this, a pivot rod 102 istransversely supported at each end in suitable bearings in upright 104of press frame F. Rotatably mounted in rod 102 at each end thereof areworm gears 106 and 108, coacting with worms 110 and 112, respectively,carried at one end of their associated worm rods 114 and 116. Activatingknobs 118 and 120 are mounted on worm rods 114 and 116 remote from theirrespective worms 110 and 112, while worm rods 114 and 116 are carried bybrackets 11 5 and 117 on uprights 104 Each worm gear 106 and 108 isassociated with a compensator roller 122 and 124 disposed parallel topivot rod 102 as shown in FIGS. 7 and 14. Roller 122 is freely supportedat each end in a pair of spaced link arms 126 and 128 rotatably carriedby rod 102. Arm 126 is fixed to and rotatable with worm gear 106 suchthat suitable rotation of knob 118 pivots roller 122 about rod 102 inthe direction of arrows C, FIG. 7.

Roller 124, in turn, is freely supported at each end in a pair of spacedlink arms 130 and 132 rotatably carried by rod 102. Arm 130 is fixed toand rotatable with worm gear 108 such that suitable rotation of knob 120pivots roller 124 about rod 102 in the direction of arrows D, FIG. 7.

In operation, when web W is out of registry between stations I and H,and it is desired to retard the web travel therebetween, knob 120 isactivated to pivot roller 124 toward web W, slightly stretching the webbetween stations I and II. This momentarily increases the tension in theweb, retarding its travel and thereby bringing web W into registry atstation II. Conversely, if it is desired to increase the rate of travelof web W between stations I and II to bring web W into registry, knob120 is activated to pivot roller 124 away from web W, relieving thetension in web W momentarily and thereby bringing web W into registry atstation II.

In like manner, roller 122 is pivoted toward and away from web W bysuitable movement of knob 118 to bring web W into registry betweenstations III and IV. It will be understood that since both rollers 122and 124 bear against the face of web W remote from the printed surface,rollers 122 and 124 in no way interfere with the successive printingoperations.

Likewise, upper compensator roller 24 is provided with means for movinglaterally to momentarily increase or decrease tension in web W betweenstations II and III to maintain web registry. Roller 24 is rotatablymounted in spaced arms 134 and 136 fixed to a cross-shaft rotatablysupported by brackets 138, 139 on uprights 104.

At one end of shaft 135, there is provided a worm gear 140 coacting witha suitable worm 142 and adapted for travel therealong. Worm 142 in turnis carried at one end of a worm rod 144 rotatably supported in bracket139 on upright 104. Knob 148 is adapted for activation of worm 142 totravel worm gear 140 therealong to pivot roller 124 against or away fromweb W as desired to speed up or retard the web travel between stationsII and III to ensure web registry therebetween.

Thus, means are provided for ensuring web registry between successiveprinting stations in the press embodying the present invention.

Ink fountain supports Each ink fountain roller 60 has associatedtherewith an inking roller 150 mounted on shaft 152 rotatably carried byink fountain carriage 68. Each inking roller 150 is adapted for rotationinto the ink supply carried by an associated ink fountain 154 at eachprinting station. Fountains 154 each include a trough 156 resting on asupport plate 158 and having an end bracket 160 (only one shown) on eachside thereof with an opening 161 for accommodating alignment studs 163.Plate 158 has fixed thereto at each'end a block member 162 slidablymounted in vertical channel brackets 164 fixed to carriages '68.

Means is provided for traveling trough 156 into and out of operativeassociation with its inking roller 150. Plate 158 rests on a pair ofspaced actuating cams 166, only one of which is shown in FIGS. 11-13.Cams 166 are fixed to and rotatable with cam shaft 168 rotatablysupported in stop blocks 170 at the lowermost ends of brackets 164.Shaft 168 likewise is provided with suitable cam shaft actuating handles172, disposed between cams 166.

In operation, plate 158 is supported at all times on a surface of cams166 only. When trough 156 is in operative position, plate 158 rests onthe flat high point 174 of cams 166 (see FIG. 11). When it is desired toremove fountain 154 from its operative position for maintenance or anink change, handles 172 are rotated in the direction of arrow B, FIG.11. This causes plate 158, now on curved face 174 of cams 166, to traveldownwardly in brackets 164 to its lowermost nonoperative position shownin FIG. 13. At this nonoperative position, plate 158 rests on the flatlow point 178 of cams 166 and trough 156 can be readily removedtherefrom by simply lifting it off its seat on plate 158.

To return fountain 154 to its operative position adjacent its associatedroller 150, movement of handles 172 is reversed, moving plate 158 andits associated trough 156 upwardly toward roller 150. This arrangementgreatly simplifies removal and replacement of ink and maintenance of theink fountain and rollers which heretofore required unbolting of thetrough for each removal operation.

It will be understood that each inking roller at each printing stationhas associated fountain mechanisms of similar construction andoperation, as described hereinabove. Further, the fountain supportmechanism on each side of the press is the same. Repetition of duplicateparts on each side of the press and at each printing station has beenomitted in the interests of clarity and brevity.

Web rewind mechanism After web W has been completely imprinted and theweb W travelled through the drying tunnel, web W is trained over idlerrollers 40 and 42 at the rewind section of the press. From idler 42, WebW passes over dancer roller 44, around idler 46 and onto rewind shaft48. Rollers 40, 42, 46 and 48 are carried in side plates 180* and 182 ofthe press frame F.

Dancer roller 44, however, is mounted on a shaft 45 carried at each endin bearing blocks 184 and 186 slidably mounted on an associated verticalslide rod 188 and 190 fixed to the top of its side plates 180 and 182.Also fixed to shaft 45 between the ends of roller 44 and blocks 184 and186 are anchors 192 and 194 to which are attached the ends of a linkchain 196 and 198, respectively. Each chain 196 and 198 in turn istrained around an associated sprocket 200 and 202 on shaft 204 rotatablycarried at the upper ends of rods 188 and 190. The other end of chains196 and 198 are each fixed to an associated lever member 206 and 208pivotally attached, as at 210 and 212, respectively, to side plates 180and 182. Each lever 206 and 208 accommodates an associated counterweight214 and 216 and levers 206 and 208 are tied together for coaction by tierod 218.

Pivotally connected to block 184 is one end of arm 220 of a suitableelectro-mechanical rotary transducer 222. Transducer 222 is preferablyof synchro-transformer having a primary energized by alternating currentand a secondary which is rotated by movement of arm 220 to produce avoltage output as a function of the dancer position. Transducer 222 isfixed to a bracket 224 on side plate 184 and is electrically connectedthrough a suitable control panel 226 and rectifier unit 228 to therewind motor 230, which is preferably a direct-current, variable speedmotor, such as, a servo-speed motor. The output shaft 232 of motor 230is provided with a drive pulley 234. Pulley 234 has trained thereaboutan endless pulley belt 236, the other end of which passes around pulley238 on rewind shaft 48.

The proper tension on web W produces the best results in rewinding. Toprovide the proper web tension, dancer roller 44 is maintained at aselected position on rods 188 and 190 for any given material. Toaccomplish this, counterweights 214 and 216 are provided tocounterbalance the selected tension force to be exerted on dancer 44 byweb W. For example, it has been found that for polyethylene and likematerial, a tension force of 6 lbs. for a 20" wide roll of 1.5 milsthickness is desirable, while for cellophane 17.6 lbs. is best for aroll 22" wide.

Other materials likewise have preferred web rewind tensions.

When tension in web W exceeds the effect of counterweights 214 and 216,dancer 44 moves downwardly, slowing motor 230. When tension in web W isless than the effect of counterweights 214 and 216, dancer 44 movesupwardly along rods 188 and speeding up motor 230.

At the start of automatic rewind, the speed of motor 230 is adjusted tothe desired rate of web rewind, normally 300-400 feet per minute, butoccasionally up to 600-700 feet per minute. As the rewound webincreases, the speed of motor 230 is adjusted by dancer 44 to maintainconstant tension of web W. As a safety, when dancer 44 has movedupwardly or downwardly to the extreme top or bottom of rods 188 and 190,transducer voltage output is zero, stopping motor 230.

Scorer mechanism To provide score lines in web W, there is provided asuitable scorer mechanism 240, coacting with idler roller 30 to cutlongitudinal scorer lines in web W as it leaves printing station IV andbefore it enters drying tunnel T. It will be understood that web W isdisposed between roller 30 and scorer 240 during the scoring operation.

Scorer 240 includes a scorer drum 242 having annular cutters 244thereon. Drum 242 is mounted on bushing 246, mounted on rod 248adjustably carried in brackets 250 and 252 on shaft 31 of idler roller30-.

To adjust the location of the score lines on the web W, bushing 246 isdisposed between arms 254 and 256 slidably mounted on rod 248 and tiedtogether by plate 258. The other end of arm 256 is provided with athreaded recess 260 and thus adapted for travel along screw member 262rotatably carried by screw support arms 264 and 266 on rod 248. Handle268 on screw 262 is provided for actuating screw 262 to travel arm 256therealong, moving scorer 240 laterally relative to web W on roller 30to the desired location for the longitudinal score lines in web W.

I claim:

1. In a flexographic press for printing multiple impressions on atraveling web at a plurality of spaced printing stations, said presshaving a plurality of impression cylinders, means rotatably mountingspaced printing plate cylinders adjacent said impression cylinders withthe axes of said printing plate cylinders parallel and generallycoplanar with the axes of said associated impression cylinders, eachprinting plate cylinder together with an associated impression cylinderconstituting a printing station, means for continuously traveling saidweb between the printing plate cylinder and the associated impressioncylinder at each station, said printing plate and impression cylindersbeing arranged such that said web in passing successively from stationto station loops back on itself with different portions of the unprintedsurface of the web facing each other and with each of said differentportions extending between a pair of said stations, whereby saidprinting plate cylinders and said associated impression cylinders areconstructed and arranged to place printed indicia on the same face ofsaid web at each of said printing stations, and means for maintainingregistry of said printed indicia as said web travels through successiveprinting stations comprising a common shaft positioned between saiddifferent portions of said web, a pair of rollers, each roller beingseparately mounted on arms which extend from said common shaft; meansfor individually rotating the arms of each of said rollers about saidcommon shaft to bring each roller into greater or lesser contact withsaid web whereby the registry of said web is maintained betweendifferent pairs of spaced printing stations.

2. The fiexographic press of claim 1 wherein said means for individuallyrotating each of said rollers on a common shaft includes a pair of armsrotatably mounting each of said rollers to said common shaft, each pairof said arms having a worm gear fixed thereto and means to operate saidworm gear including a gear, an operating shaft extending from said gearand an operating handle aflixed to said shaft.

3. In a flexographic press for printing multiple impressions on atraveling web at four spaced printing stations, said press having upperand lower impression cylinders with their respective axes substantiallyparallel and disposed in a generally relationship, means rotatablymounting a pair of spaced printing plate cylinders on opposite sides ofand adjacent each of said upper and lower impression cylinders andhaving the axes of each of said pair of printing plate cylindersparallel and generally coplanar with the axes of associated impressioncylinders, means for continuously traveling said web between saidprinting plate cylinders and said upper and lower impression cylindersthereby forming a generally inverted U-shaped web con-figuration throughsaid printing stations whereby said printing plate cylinders and saidassociated impression cylinders are constructed and arranged to placeprinted indicia on the same face of said web at each of said printingstations and means for maintaining registry of said printed indicia assaid web travels through successive printing stations comprising a pairof rollers, a pair of arms for independently rotatably mounting each ofsaid rollers on a common shaft to contact the nonindicia bearing surfaceof said web at opposite sides of said inverted .U-shaped configuration,and between a pair of spaced printing stations, the axis of said commonshaft being positioned parallel to and between said impressioncylinders, said mounting means for each roller including a pair of armsone end of each of which is rotatably mounted about said common shaftand the other end rotatably supporting said roller and means forindividually rotating each of said rollers about said common shaft andinto greater or lesser contact with said web whereby the registry ofsaid Web is maintained between said pair of spaced printing stations.

4. The flexographic press of claim 3 wherein said means for individuallyrotating each of said rollers on a common shaft includes a pair of armsrotatably mounting each of said rollers to said common shaft, each pairof said arms having a worm gear fixed thereto and means to operate saidworm gear including a gear, an operating shaft extending from said gearand an operating handle affixed to said shaft.

References Cited UNITED STATES PATENTS 1,643,324 9/1927 Waller 1011521,855,525 4/1932 MacArthur 101181 X 1,959,436 5/ 1934 Marston et al.101181 2,542,229 2/ 1951 Bojanower et al 101-182 2,570,045 10/1951Bojanower et al. 101181 2,764.087 9/1956 Stobb 101-181 ROBERT E.PULFREY, Primary Examiner.

J. R. FISHER, Assistant Examiner.

US. Cl. X.R. 101228

